In a compressor used in a refrigerating cycle, when oil flows out to an external cycle from the compressor, not only is a shortage of oil in the compressor brought about, but also the oil circulates in a cycle together with a refrigerant thus giving rise to a drawback that refrigerating efficiency is lowered.
To avoid such a drawback, the applicant of the present application previously proposed a compressor having the constitution where a working fluid is introduced into a suction chamber from a suction port through a crank chamber. To explain the constitution of the compressor, in a shaft which penetrates the crank chamber, at least an axial hole and a side hole are formed. The axial hole extends along the axial direction of the shaft, and the side hole communicates with the axial hole, extends along the radial direction of the shaft and opens to the crank chamber. A working fluid which flows into the crank chamber is introduced into the suction chamber through at least the side hole and the axial hole, and by making use of a centrifugal separating operation generated due to the rotation of the shaft, any oil in the working fluid which flows into the suction chamber from the crank chamber is separated when the working fluid flows through the side hole opening to the crank chamber (see patent document 1).
However, in such constitution, in an attempt to introduce a total quantity of working fluid flowed from the suction port into the suction chamber by allowing the working fluid to pass through the side hole and the axial hole formed in the shaft, a flow speed of the working fluid becomes fast at an inlet of the side hole formed in the shaft so that the centrifugal separating operation does not function effectively. Accordingly, oil mixed into the working fluid is sucked out to the suction chamber and, eventually, a quantity of oil discharged to the outside of the compressor cannot be sufficiently suppressed.
In view of the above, the applicant of the present application has proposed the constitution where, in addition to a suction path where a working fluid which flows into a crank chamber is allowed to pass through a shaft and is introduced into a suction chamber, there is provided another suction path where the working fluid which is sucked from a suction port is introduced into the suction chamber without via the crank chamber so that a part of the sucked working fluid is made to pass through the inside of the shaft from the crank chamber and a remaining part of the sucked working fluid is directly introduced into the suction chamber (see patent document 2).
Due to such constitution, a flow speed of the working fluid which is sucked from a side hole formed in the shaft slows down so that a sufficient oil separation function can be acquired.